A solid electrolytic capacitor is used for removing noise generated in a device such as a CPU or for stabilizing power supply to an electronic apparatus (see e.g. Patent Document 1). FIG. 21 shows an example of such a solid electrolytic capacitor. The solid electrolytic capacitor X includes a porous sintered body 90 made of metal having a valve function. An anode wire 91, which is an example of anode conduction member, is provided to partially project from the porous sintered body 90. A conductive film 92 constituting a cathode is formed on the porous sintered body 90. Conductive members 93 and 94 are electrically connected to the anode wire 91 and the conductive layer 92, respectively. The conductive members 93 and 94 include portions exposed at a sealing resin 95, and the exposed portions serve as an anode terminal 93a and a cathode terminal 94a for surface mounting. Herein, the frequency characteristics of the impedance Z of a solid electrolytic capacitor are determined by the following formula 1.Z=√{square root over ((R2+(1/ωC−ωL)2))}  Formula 1:
In Formula 1, ω represents angular velocity, which is equal to 2π times the frequency, C represents capacitance of the solid electrolytic capacitor, R represents resistance, and L represents inductance. As will be understood from the formula, in a frequency region lower than the self-resonant frequency, 1/ωC is the major determinant of the impedance Z. Therefore, the impedance can be reduced by increasing the capacitance C. In a high frequency region close to the self-resonant frequency, the resistance R is the major determinant. Therefore, to reduce the impedance, it is necessary to reduce the ESR (equivalent series resistance). Further, in an ultra high frequency region higher than the self-resonant frequency, ωL is the major dominant. Therefore, to reduce the impedance, it is necessary to reduce the ESL (equivalent series inductance).
Recently, from a device such as a CPU with a high clock frequency, high frequency noise including a harmonic component is generated. Further, in accordance with an increase in speed and digitalization of electronic devices, a power supply system capable of quickly responding to power demand is demanded. Therefore, for a solid electrolytic capacitor X to be used for these devices, a reduction in ESL is strongly demanded. For instance, as a means to reduce the ESL, it may be considered to make the porous sintered body 90 flat. However, as the porous sintered body 90 becomes flatter, the thickness of the porous sintered body 90 at a portion covering the anode wire 91 reduces. Therefore, when an external force is applied to the anode wire 91 in the process of manufacturing the solid electrolytic capacitor X, for example, the porous sintered body 90 may break and the anode wire 91 may drop from the porous sintered body 90. In this way, when the thickness of the porous sintered body 90 is reduced to reduce the ESL, the bonding strength of the anode wire 90 becomes insufficient.
Patent Document 1: JP-A-2003-163137 (FIG. 15)